The invention relates to a device for driving one or several pile carriers for the selection of one or several pile yarns. More particularly the invention relates to such a device comprising at least one drive motor for driving a pile carrier, the pile carrier moving under the motor housing and the motor shaft of the drive motor being provided with driving means for driving the pile carrier directly.
Up to this moment, similar devices for driving one or several pile carriers for the selection of one or several pile yarns, were mainly used with gripper axminster weaving machines.
In BE 1 010 005 a device is described indeed for guiding and moving pile carriers in a gripper axminster weaving machine. In this device, the pile carriers are brought from one position into the other by directly controlled linear motors. The selection movement remaining restricted to the displacement over that distance between two successive selection positions.
This device has the disadvantage that the linear motors require very exact linear guides in order to absorb the mutual attractive forces between windings conducting electric current and permanent magnets exiting magnetic fields. These linear guides and the linear motors are relatively expensive. Linear guides require a good lubrication and therefore careful maintenance is required.
In EP 1 029 959 a device is described for guiding and driving pile carriers, based on the use of classic motors with rotating armature. In these devices a drive motor with rotating armature is coupled to each pile carrier. This coupling always occurs, according to the figures represented, by means of an auxiliary driving means, such as a gear belt and a gear wheel, functioning as an intermediate wheel or simply a gear wheel as an intermediate wheel.
The disadvantage of this device is that it requires more transmission components with additional bearings, causing more wear and tear and therefore relatively much maintenance. Moreover these intermediate wheels will cause more clearance in the driving system, so that the precision of the activated positions is lost. Because of which the pile yarn is no longer positioned exactly above the rapier jaws. This is the cause of the fact that the rapier jaws fail to catch the yarn presented and will cause the stop-motion of the pile yarn to bring the weaving machine to a halt.
These drawbacks are remedied in EP 1 156 146, in which a device and a method are described, with which 12 or 24 yarns of different colors are found on a selector wheel and a motor being provided which is able to bring the selector wheel in different angular positions in order to present the color desired to the yarn conditioner, presenting the yarn to the rapier by rotating over an angle of 180°. The yarn conditioner is provided for serving different rapiers, for instance 8, by means of the selector wheel during the time available. In this manner the selector wheel will not have to wait till the rapiers return from the shed in order to present the pile yarns to the 8 rapiers for the next weaving cycle, but the selector wheel may start immediately after the yarn conditioners will simultaneously present all pile yarns to the rapiers by turning a 180°, by presenting the pile yarns one by one in the other holders for the next cycle.
The disadvantage of this method is, that such a selector wheel takes up more width of the weaving machine per selector. When the selector wheel may be kept smaller than the drive motor, the cross-section of the motor becomes the restricting factor for arranging the selectors side by side.